Such a device is described in U.S. Pat. No. 4,669,592 and the corresponding French patent publication FR 2 560 328A, in which the damper plate is moveable with respect to a hub within the limits of a said range of relative angular displacement, while the hub is adapted to be secured to the primary shaft of the gearbox for rotation therewith. One of the guide rings is freely mounted with respect to the hub and carries a support member fitted with the clutch friction pads which couple the primary shaft of the gearbox to the crankshaft of the vehicle. The damper plate can of course be fixed to the hub. A bearing of L-shaped cross section is also provided. This bearing has an axially extending element and a radially extending element, and is interposed between the hub and one of the guide rings.
In that type of damper, the driven shaft may not be perfectly aligned with the driving shaft, but can become radially offset and inclined at an angle with respect to it. In operation, this results in axial and radial forces occurring within the friction disc clutch. This is aggravated by the fact that manufacturers tend to omit the bearing mounted at the end of the crankshaft and carrying the end of the driven shaft, so that the latter is mounted out of true, which further accentuates the axial and radial forces mentioned above.
In order to overcome this disadvantage, it could be proposed that the axial portion of the bearing might be made radially resilient, but such an arrangement may prove insufficient in the case where the shafts are inclined at an angle with respect to each other, since it will not allow the axial forces to be minimised as is desirable, and as is indeed required because of the presence of the radial element of the bearing which constitutes a spacer between the guide ring concerned and the hub. This solution is also difficult to apply in practice when the guide rings are fixed to the hub, with the damper plate freely mounted with respect to the hub.